Method and device for fabricating posts made of concrete or the like with polygonal cross section

ABSTRACT

A method and device for fabricating posts made of concrete having a polygonal cross-section includes the steps of providing and opening an integral liner, applying backing panels to the liner, holding the panels together with a hooping means, and pouring and hardening concrete in the integral liner. The liner is collapsible and preformed to open in the shape of a right prism with an internal section identical to that of the post to be manufactured. Backing panels made of cardboard or plastic material support the external faces of the liner and entirely cover the external faces of the liner. At least one of the backing panels is adhered to an external face of the liner. A hooping means holds the liner and the backing panels assembled in mutual contact during the use of the device.

BACKGROUND OF THE INVENTION

The present invention concerns a process and a device for themanufacture of posts of concrete or the like, of polygonal crosssection.

It is known that the preparation of concrete structural elementsinvolves the use of forms of wood or metal in which the concrete ispoured and where it is left to harden. These forms are expensive andheavy and difficult to handle. Furthermore, on the worksites theoperations of setting and stripping forms are often difficult.

In the case of simple pieces such as posts, it has already been proposedto cast the concrete in simple cardboard sheaths. The tests performedfor posts of circular section have proven perfectly satisfactory, andthis process is now employed in the art. It offers the advantage ofbeing very easy to employ and of being much less expensive than theordinary methods using complex forms.

Despite these advantages, it has not been possible, however, to applythis process to the production of posts of polygonal (square,rectangular or other) cross section, for in every case the cardboardsheath used deforms by sagging to assume a circular or rounded section.

To remedy this problem, it has been proposed, in FR-A-1 453 489, to makeuse of a cardboard form of polygonal section, which is reinforced byapplying boards to its external faces, these boards being held inposition against the faces of the form with the aid of clamps.

GB-A-648,809 has also proposed using for this purpose a form ofpolygonal section constituted by a plaster panel gripped between twocarboard boards, this panel having parallel folding lines enabling it tobe folded to form a liner which is externally sheathed in a protectivesheet of paper, fabric, leather etc.

All these processes, however, are expensive and difficult to employ.

The present invention aims to remedy this problem by proposing a processfor making concrete posts of polygonal cross section that will be aseasy to employ as the cardboard sheath process used for the manufactureof posts of circular section, that will not be more expensive than thelatter, and which will use, for the pouring of the concrete and forsetting it, not a wooden form but a simple liner which does not deform.

SUMMARY OF THE INVENTION

The subject matter of the invention is a process for making posts ofconcrete or the like of polygonal cross section, characterized in thatthe concrete is poured and allowed to set in an integral liner in theshape of a right prism, having an internal section identical to that ofthe post, this liner being duplexed externally on all its faces tobacking panels of a rigid or semi-rigid material which cover the saidfaces, and at least one of which adheres to an external face of theliner, the liner and the associated backing panels being held togetherin contact with one another, in the position of use, by hooping means orthe like.

The invention also has as its subject matter a device for making postsof concrete or the like, of polygonal cross section, characterized inthat it includes an integral liner in the form of a right prism havingan internal section identical to that of the post, backing panels of arigid or semi-rigid material adapted to be applied against the externalfaces of the liner to cover them on their entire surface, one of whichadheres to one external face of the liner, and hooping means or the likeadapted to hold the liner and the associated backing panels in contactwith one another during the employment of the device.

The posts of concrete or the like of polygonal cross section made by theprocess or with the aid of the device defined above constitute anothersubject of the invention.

The liner used can be of cardboard, plain or corrugated, treated ifdesired with any means known in itself, of special cardboard includingflat cover sheets of cardboard between which is interposed at least onearmature other than a corrugated sheet, or again, a plastic materialsuch as polyethylene, an expanded high-density plastic material,rotary-cut wood veneer, or the like.

Advantageously, the liner is in the form of a unit that can be foldedflat by bending it on folding lines or creases coinciding with thearrises of this liner. The liner can be derived from a single blank ofcardboard appropriately cut and creased, whose two free margins parallelto the folding lines will be brought substantially into edge-to-edgecontact with their adjacent portions glued to a same backing piece.

These pieces can be contiguous with one another two-by-two to form aplanar structure in which areas of lesser thickness define the foldinglines separating the different elements, the liner being glued at oneexternal face to one of these elements. In the case where the liner hasa square rectangular cross section or one in the form of aparallelogram, the assembly thus formed will be able to be deliveredflat to the users after the liner has been folded.

In another embodiment, two backing panels can adhere to two parallelexternal faces in the position for the use of the liner, to form aflat-folding assembly, the other backing elements being removable andapplied to the corresponding faces of the liner at the time of use. Inthe case of a liner of square or rectangular cross section, the backingpanels glued to two parallel faces of this liner can advantageouslyoverlap with respect to these faces by a distance at least equal to thethickness of the panels, whereas the other elements will have a widthexactly equal to that of the other faces of the liner, so as to havetheir edges in contact with the overlapping portions of the contiguouspanels when in the position of use, and to be thus gripped between theseportions.

The hooping means can be simple metal or plastic straps.

In another embodiment, two of the backing panels will adhere to twoparallel external faces, in the position of use, of a first integralliner in right-prism form, while the other backing panels will adhere tointernal faces of a second integral liner constituting the hoopingmeans, the two liners equipped with their backing panels cooperating bythe fitting of the first liner into the second liner.

In this embodiment, additional hooping means such as straps can also beprovided.

In all of the embodiments, folding flaps can, of course, be provided ateach end of the liner to mask the internal structure.

Of course, other embodiments of the device according to the inventioncan be conceived by a person of ordinary skill in the art withoutdeparting from the scope of the invention.

This device is distinguished from wooden or metal forms of the prior artby its extreme simplicity, its lightness, and its ease of use on theworksites, where its placement in position for use is performed verysimply, without the use of special tools or requiring special handlingapparatus.

It will be noted, furthermore, that after the concrete post has beenmade, the liner can be separated from it by tearing it off, but that theelements of plastic material and the hooping means are not altered bythe employment of the process and they can therefore be recovered foranother use.

With all the variants of the device according to the invention, theApplicant has established that it is possible to make concrete posts ofpolygonal cross section without the least sagging or the leastdeformation of the liner, even though made of cardboard, and to obtainfinished products of a quality at least equal to that of posts made withthe forms of the prior art.

These advantages will clearly appear from the detailed description thatfollows of various embodiments of the invention. These embodimentsrelate to the production of posts of square section, but the invention,of course, is not limited to such posts and instead applies to theproduction of posts having any polygonal cross section.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are perspective views of a preassembled liner and backingpanels of a first embodiment of the device according to the invention,with the liner represented flat and deployed in position of use,respectively;

FIG. 3 is a perspective view of the first embodiment in position of use,with the different elements assembled with the aid of strapping;

FIG. 4 is an exploded view of another embodiment of the device accordingto the invention;

FIG. 5 shows the elements of FIG. 4 assembled in position of use withthe aid of strapping.

FIG. 6 is a view similar to FIG. 5 of a third embodiment of the deviceaccording to the invention.

FIGS. 7 and 8 are perspective views of two parts of the embodiment inFIG. 6, in position of assembly;

FIGS. 9 and 10 are perspective views of the parts of FIGS. 7 and 8,folded flat.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the embodiment in FIGS. 1 to 3, the cardboard liner 1 in which theconcrete is cast has a square cross section and is obtained from asingle cardboard blank appropriately cut and scored, while the backingpanels 2 of plastic material are also contiguous two by two and form asingle panel3 in which creases 4 define the folding lines. The liner 1is glued by one of its faces to an element 2 of the panel 3, the gluedface having been made, as seen in FIGS. 2 and 3, by bringing the lateralportions of the starting cardboard sheet edge to edge in the same plane.

As represented in the drawings, to bring these elements into theposition of use, the cardboard liner 1 is opened up, the correspondingbacking panels 2 are folded against its lateral faces to form atransversely closed structure, and these elements are assembled in thisposition by means of straps 5 of metal or plastic material.

The setting up of the device at a worksite is therefore extremely simpleand, as indicated above, after the concrete post has been cast, theliner 1 can be separated from it by tearing it away, while the panel 3of backing elements 2 and the straps 5 can be recovered and reused foranother cycle of operations.

The same is the case with the embodiment in FIGS. 4 and 5 in which thecardboard liner is similar to the liner 1 described above. On twoparallelexternal faces of this liner 6 there are glued two backingpanels 7 of plastic material, which laterally overlap each side of thecorresponding face of the liner 6 by a distance equal to the thicknessof the panels. Itis thus possible to engage between the panels 7 twopanels 8 of a width equal to that of the faces of the liner 6, to setthem against the two free faces of the liner.

As before, the straps 9 hold the different elements assembled inposition of use.

This second embodiment is as simple as the one before, and as easy touse at the worksite. In this second embodiment, likewise, the panels ofplastic material 7 and 8 and the straps 9 can be recovered at the end ofthe fabrication cycle for reuse.

In the variant of FIG. 6, two backing panels 10 of plastic material arealso glued onto two parallel external faces of a cardboard liner 11 ofsquare cross section, in which the concrete is poured, but the backingpanels 12 which are applied to the other external faces of the liner 11are glued against the two corresponding internal faces of a second liner13 in which the liner 11 and the panels 12 can be engaged by sliding.For this purpose, the panels 10 have a width substantially equal to thecorresponding internal dimension of the cross section of the liner 13,while the panels 12 have a width substantially equal to thecorresponding external dimension of the liner 11.

As can be seen in FIGS. 7 to 10, the liners 11 and 13 equipped,respectively, with the panels 10 and 12 can thus be folded flat anddelivered to users or stocked in this form. Unfolding them is performedeasily at the worksite, without the need for special tools.

In this variant, the hooping is constituted by the liner 13 itself, butof course metal or plastic straps can be added as in the otherembodiments.

The invention therefore provides a simple and easy-to-use means formaking concrete posts of polygonal cross section at the worksite.

It will be appreciated that the present invention can be embodied inother specific forms without departing from the spirit or centralcharacteristics thereof. The presently disclosed embodiments arethereforeconsidered in all respect to be illustrative and notrestrictive. The scopeof the invention is indicated by the appendedclaims, and all changes that come within the meaning and range ofequivalents thereof are intended to be embraced therein.

What is claimed is:
 1. A device for the manufacture of posts of concretehaving a polygonal cross section, including:an integral collapsiblefirst liner, having a number of external faces extending betweenparallel creases, preformed to open in a shape of a right prism, thefirst liner having an internal section when open identical to that ofthe post to be manufactured; backing panels made of one of cardboard,corrugated cardboard, and plastic material, the backing panels being ofa number equivalent to the number of external faces of the liner andadapted to be applied against all the external faces of the first linerso that the backing panels entirely cover the external faces of thefirst liner, wherein the backing panels are distinct from the firstliner and at least one of the backing panels is adhered to at least oneof the external faces of the first liner; and first hooping means forholding the first liner and the associated backing panels assembled inmutual contact during the manufacture of the concrete posts with thedevice when the integral first liner is opened in the shape of the rightprism.
 2. A device according to claim 1, wherein the first linercomprises:a single blank appropriately sized and provided with theparallel creases, two free borders of the blank parallel with thecreasing being substantially in edge-to-edge contact, wherein externalfirst liner surfaces adjacent to the two free borders are glued againsta common backing panel and wherein the first liner is collapsible bybending at its creases.
 3. A device according to claim 1, wherein thebacking panels are a mutually contiguous two-by-two planar structurehaving zones of lesser thickness which define folding lines to separatedifferent panels, and wherein one external face of the first liner isglued to one of the backing panels.
 4. A device according to claim 1,wherein two of the backing panels are adhered to two parallel externalfaces of the first liner in an opened position, the remaining backingpanels being removable and applied to remaining faces of the first linerduring use.
 5. A device according to claim 4, wherein the first liner isone of rectangular and square cross-section, and wherein the backingpanels that are glued to two parallel faces of the first liner laterallyoverlap with respect to the parallel faces, by a distance substantiallyequal to a thickness of the remaining panels, and wherein the remainingpanels have a width substantially equal to a width of the remainingfaces of the first liner.
 6. A device according to claim 1, wherein thefirst hooping means are straps made from one of metal and plastic.
 7. Adevice according to claim 1, wherein two of the backing panels areadhered to two parallel external faces of the first liner, and whereinthe remaining backing panels are adhered to internal faces of a secondliner, the second liner functioning as the first hooping means; thefirst liner with its two backing panels being adapted to slideably fitinto the second liner having the remaining backing panels adheredthereon.
 8. A device according to claim 7, including a second hoopingmeans in the form of straps made from one of metal and plastic.
 9. Thedevice of claim 1 wherein the integral first liner is made of one ofcardboard, corrugated cardboard, and plastic.
 10. A process for themanufacture of posts of concrete having a polygonal cross-section,comprising the steps of:providing an integral collapsible liner, havinga predetermined number of external faces extending between parallelcreases, preformed to open in a shape of a right prism and a pluralityof backing panels equal in number to the predetermined number ofexternal faces of the liner, at least one of the backing panels beingadhered to at least one of the external faces of the first liner;opening the integral liner into the shape of the right prism with aninternal section identical to that of the post to be manufactured;applying the backing panels made of one of cardboard, corrugatedcardboard, and plastic to all the external faces of the first liner toentirely cover all external faces of the liner, the backing panels beingdistinct from the liner and at least one of the backing panels adheringto at least one of the external faces of the liner; holding the openedliner and the backing panels in mutual contact with each other withhooping means; pouring concrete into the liner and allowing the concreteto harden while the backing panels and hooping means prevent thedeformation of the liner; removing the hooping means; and removing thebacking panels and the liner from the manufactured concrete post ofpolygonal cross-section.
 11. The process of claim 10, wherein the stepof opening the liner includes the step of opening the liner made of oneof cardboard, corrugated cardboard, and plastic.